This would unfortunately be confusing since iron is already a rust web framework.

But the language is named after tree mould, not oxidized metal. :Shrug:

"Iron" seems like a fun/nice option.

Could call it Oxygen, or Oxidize, or something along those lines

The Fe foundation, or "FeFo" in short.

Personally I think anything beyond "Rust Foundation" or "Rust Language Foundation" risks merely confusion over purpose.

The "Ferrous Foundation" is appealingly alliterative. But it also makes it easier to expand the focus beyond Rust — which is probably a negative, because it makes it harder to concentrate on core competency.

Every foundation is engaged in a perpetual struggle over whether to expand its mission. But in the vast majority of cases, mission creep weakens the organization's ability to achieve its primary goals.

(Crafting a concise mission statement will help inoculate against mission creep, and should be done regardless.)